The hard part is not the software. It is the empty page. Do not write an About page. Write three sentences, in this order.
1. What you fix
Not your job title. The problem someone has before they think of you.
"I find out why a WordPress site costs more to host than it should." "I fix checkouts that lose orders." "I write the docs nobody on your team has time to write."
If a stranger cannot tell from this line whether they have the problem, it is too vague. "Full-stack developer" is a job, not a problem.
2. Who you fix it for
Narrow beats broad. "I help small businesses" tells a reader nothing. "I help Shopify stores doing $50k a month or more" tells them at once.
It will feel like turning people away. It is. The people who stay know they are in the right place.
3. What it costs and how to start
A price and a button. Most people leave this out. It is the line that decides whether a stranger hires you today or forgets.
Then add proof
Once the three sentences are down, add anything that shows you can do the work. A short post about a problem you solved. A two-minute video of how you would go about it. A before and after. This does more than a portfolio, because it shows how you think.
You can add it later. Put the three sentences up today.